1. Field of the Invention
The present invention relates to a method for preparing the arylphosphonite antioxidant and, more particularly, to a method for preparing the bifunctional arylphosphonite antioxidant that has both the first grade and second grade anti-oxidation functions.
2. Description of the Related Prior Art
The uses of antioxidants are to retard or forbid oxidation of plastic materials, thereby extends the usage time of the materials. At present, the main classification of antioxidants is hindered phenols, phosphites, thioethers. Hindered phenol is the most popular first grade antioxidant. Taking 1010 and 1076 as stand for the macromolecular hindered phenols, where the market consumption of them unceasingly increases, and in recent years the trend of domestic production rate of 1010 and 1076 are doubling. Aside from the first grade antioxidants, the second grade antioxidants TNPP and 168 are the chief products of phosphites, the manufacturing techniques of TNPP and 168 are fully developed at the same time and market is stable. There are dialkylthiodipropionate of thioethers auxiliary antioxidants that are still in production in industry, therefore the variety of thioethers auxiliary antioxidant are much simpler with respect to other groups.
However, the aforementioned antioxidants consist only of single anti-oxidation function, they can only either be first grade or second grade antioxidant but not both.